Field of the Invention
The present invention is broadly concerned with dough relaxers made up of natural ingredients, as well as methods of use thereof and resultant dough formulations. More particularly, the invention is concerned with dough relaxers produced by pre-treating or pre-reacting wheat protein with non-leavening yeast and/or yeast extract; such relaxers may then be used in conventional dough formulations to obtain desirable relaxation properties.
Description of the Prior Art
It is known that redox (reduction-oxidation) reactions involving wheat flour sulfhydryl (SH) groups and disulfide bonds have a significant effect on structure of gluten proteins, and are considered crucial to dough rheology and bread-making performance (Fitchett and Frazier 1986; Grosch 1986). In the past, dough relaxers or reducing agents have been added to wheat-based doughs to improve the extensibility, sheeting properties, and overall machinability of the doughs. In flour tortillas, for example, reducing agents are commonly used to shorten resting times before pressing by increasing the extensibility and decreasing elasticity of gluten proteins within the tortilla doughs. This is achieved using compounds such as L-cysteine, sodium metabisulfite, sorbic acid or fumaric acid, which break disulfide bonds (Van Eijk and Legel 1996). While L-cysteine is quite effective, it is derived from animal sources (hair or feathers). Sodium metabisulfite is also chemically derived and is considered an allergen.
The resistance of consumers to chemical additives and their propensity to desire more natural additives is growing. Therefore, commercial suppliers of wheat-based products would like to be able to offer “natural” additives to meet consumer preferences.
Heretofore, materials such as soy flour, wheat germ, garlic, and inactivated dry yeast have been proposed as dough relaxing agents or mix time reducers, because they are a good source of low molecular weight SH compounds such as L-cysteine and/or glutathione. However, these materials are not as effective as animal-derived or synthetic chemical relaxers. There is therefore a need in the art for improved dough relaxers which are fully effective while avoiding the use of traditional dough relaxing ingredients.
The following references describe the prior research on wheat proteins, dough relaxers, and dough formulations containing conventional relaxers: U.S. Pat. Nos. 4,643,900; 5,510,126, 5,576,036; 5,763,741; 5,792,499; 5,859,315; 6,436,459; and 8,309,152; US Patent Applications Nos. 2004/0146601; 2008/0254200; PCT Publication Nos. WO 2006009447 A1 and WO 2013092731 A1. Cha, J.-Y., Park, J.-C., Jeon, B.-S., Lee, Y.-C. and Cho, Y.-S. 2004. Optimal fermentation conditions for enhanced glutathione production by Saccharomyces cerevisiae FF-8. J. Microbiol. 42(1):51-55. Chen, X. and Schofield, J. D. 1996. Changes in glutathione content and bread-making performance of white wheat flour during short-term storage. Cereal Chem. 73(1):1-4. Fitchett, C.S. and Frazier, P.J. 1986. Action of oxidants and other improvers. Pages 179-198 In: Chemistry and Physics of Baking, J. M. V. Blanshard, P. J. Frazier and T. Galliard, eds., Royal Society of Chemistry: London. Frater, R. and Hird, F. J. R. 1963. The reaction of glutathione with serum albumin, gluten and flour proteins. Biochem. J. 88:100-105. Grosch, W. 1986. Redox systems in dough. Pages 155-169 In: Chemistry and Physics of Baking. J. M. V. Blanshard, P.J. Frazier and T. Galliard, eds., Royal Society of Chemistry: London. Sakato, K. and Tanaka, H. 1992. Advanced control of glutathione fermentation process. Biotechnol. Bioeng. 40:904-912. Wei, G., Li, Y., and Chen, J. 2003a. Effect of surfactants on extracellular accumulation of glutathione by Saccharomyces cerevisieae. Process Biochem. 38:1133-1138. Wei, G., Li, Y., and Chen, J. 2003b. Application of a two-stage temperature control strategy for enhanced glutathione production in the batch fermentation by Candida utilis. Biotechnol. Lett. 25:887-890.